The present invention relates to a structure of an angle portion of an endoscope.
FIG. 3 is an entire side view of an industrial or medical endoscope. The conventional technique will now be described with reference to FIG. 4, which is a side view illustrating the main part of the endoscope.
In the drawings, reference numeral 1 represents a flexible tube, reference numeral 2 represents a handle and reference numeral 3 represents a conduit, and the endoscope is constructed so that the flexible tube is inserted into the body to be observed and the interior of the body is observed.
More specifically, a distal tip 4 is located on the top end of the flexible tube 1, and an observing window, an illuminating window, an air-jetting and water-jetting opening, a sucking opening, a forceps opening and tope ends of various articles to be introduced according to need are arranged in the rigid tip end portion 4. Reference numeral 5 represents an angle portion continuous to this rigid top end portion 4 and comprises continuous rings arranged so that the posture of the distal tip 4 is changed in up-and-down and left-and-right four directions, as described hereinafter. The present device relates to this angle portion.
The handle 2 comprises operating knobs 6a and 6b for changing the direction of the distal tip 4, and the operating knobs 6a and 6b are arranged so that an operating wire passed through the interior of the flexible tube 1 is operated by the knobs 6a and 6b to change the direction of the distal tip 4. Reference numeral 7 represents an eyepiece portion, and an image guide or C.C.D. is laid out between the eyepiece portion and the observing window.
A light guide for guiding light to the illuminating window, an air and water feed pipe and a sucking pipe are arranged within the conduit 3 so that these members can be connected to a light source and a pump.
In the above-explained endoscope, the angle portion 5 comprises rings 8a and 8b connected to each other and tunably arranged at positions different by 90.degree. as shown in FIG. 4 and a cover capped on the periphery, and these rings of the angle portion are arranged to that the operating wire not shown in the drawings is operated by the operating knobs 6a and 6b of the handle 2 to turn the distal tip 4 in the desired direction among the up-and-down and the left-and-right directions, as pointed out hereinbefore.
According to the above-mentioned conventional technique, for example, when the inlet of the stomach is observed, the angle portion is caused to make a U-turn for the observation. Namely, the angle portion is turned upward and the posture is changed in the left-and-right direction.
In this case, the posture of the observing window of the distal tip 4 is not changed in the left-and-right direction as shown in FIG. 6 and only the upwardly bent part is moved in the left-and-right direction as shown in FIG. 5, and the observing window of the distal tip 4 is directed to the center and the flexible tube is located in the central portion of the visual field.
Also, since the connecting part between the distal PG,4 tip 4 and the angle portion 5 also acts as a connecting part for the article to be introduced, bending of this connecting part is rendered difficult by the resistance of the article. Since the operating wire is operated to forcible change the direction of the connecting part, heavy loads are imposed on the article introduced and the operating wire, resulting in degradation of the durability.